Process of separating or extracting, from oils and fats, the unsaponifiable fraction possessing the vitamin potency present therein



c. L. BARTHEN 1,984,858

ND FATS THE UNSAPONIFIABLE FRACTION POSSESSING THE VITAMIN POTENCY PRESENT THEREIN Dec. 18, 1934.

PROCESS OF SEPARATING OR EXTRACTING'F-ROM OILS A 'Fled May '5, 1955 SOLVENT XTRACTED SOAP SOAP SOLUTION 5 O LVE NT EXTRACT Y L 9W ATTORNEYS Patented Dec. 18, 1934 UNITED STATES PATENT OFFICE PROCESS OF SEPARATING R EXTRACT- ING, FROM OILS AND FATS, THE UN- SAPONIFIABLE' FRACTION POSSESSING THE VITAMIN POTENOY PRESENT THEREIN I Charles L. Bar-then, South Orange, N. J., as-

signor to Health Products Corporation,

Newark, N. J., a corporation of New Jersey Application May 3, 1933, Serial No. 669,120 4 Claims. (01. 167-81) 5 more specifically a particular example, the invention relates to a process for producing a concentrated preparation of the anti-xerophthalmio and growth-promoting vitamin A and the antirachitic vitamin D, both of which are oil or fat soluble vitamins.

These vitamins areknown to be contained in' various oils and fats, for example, and to name an economical source, cod liver oil. It is an established fact that the vitamin potency is present in the unsaponifiable fraction of the fats oroil suchas cod liver oil, and the separation of the unsaponifiable fraction has therefore been the object of considerable research and experiment;

A particular object of the invention is to provide a method for the production of a vitamin A or vitamin D concentrate, or a concentrate of both vitamin A and vitamin D, which avoids certain difliculties heretofore encountered in other processes.

For example, most processes heretofore suggested for the separation or extraction of the unsaponifiabie fraction of cod liver oil or other vitamin-bearing oil are either based on the classical method for determining the unsaponifiable mat-- ter in oil and fat, or are modifications of the classical method. A serious difilculty encoun tered in all the processes suggested that the soap present either absorbs, dissolves, or emulsifies the solvent employed to extract the unsaponifiable fraction to such a degree that the soap present has a tendency to prevent the complete removal of all the unsaponifiable matter held in suspension in the soap mixture or solution. Because 01' this, in order to insure complete or nearly complete removal or extraction of the unsapon'ifiable matter, it is necessary to subject the soap mixture to a series or" washings with the solvent. This procedure requires not only an enormous 'quantity of the extracting solvent, but also long periods of time for the settling or separation of the extracting solvent from the soap mixture following each agitation or washing outot the unsaponifiable matter with the extracting solvent.

It is a particular object oi. the present invention to provide a method for the purpose stated in which the soap present has no tendency to prevent the complete removal of all the unsaponifiable matter, whether by absorbing, dissolving, or emulsifying the solvent, or otherwise.

Further objects of the invention are to eliminate the series of agitations and washings of the soap solution with the extracting solvent, as well as to eliminate the loss of time now occurring by reason of the necessary periods of waiting for the settling or separation of the extracting solvent from the soap mixture following each agitation or washing thereof with the extracting solvent.

Another object is to provide such a method or process which requires only a relatively small amount of solvent as compared with other already known processes.

Another object is to provide a novel process for -the preparation of a soap solution from vitamincontaining material, such as cod or other fish liver oil, or other vitamin-bearing oil, from which soap solution the unsaponifiable fraction containing the vitamins is to be separated.

Another object of the invention is to provide, in connection with the preparation of the soap solution, a method for the continuous extraction therefrom of the unsaponifiable fraction.

It is more specifically an object of the invention to provide such a continuous process by which all the vitamin-containing material is removed; in which the soap present does not interfere with such complete removal; in which agitations and repeated washings with the solvent are eliminated; and. in which only a relatively small amount of extracting solvent is required. p

Other objects and advantages oi the invention will be apparent from the iollowing detailed description. The drawing illustrates, in elevation and more or less diagrammatically, a form of apparatus for the continuous extraction of the unsaponifiable fraction from the prepared soap solution in accordance with the invention.

For illustration, a specific, and at present a preferred, example of the practice of the invention will be given, though it will be understood that the invention is not restricted to this specific exafnple, which may be varied in .practice withoutdeparting from the invention as defined by the appended claims.

Referring first, then, to the preparation of the soap solution in accordance with such specific example:

Into a soap cooker or other suitable vessel are introduced 400 gallons (or 3,000 pounds) of cod liver oil or other vitamin-bearing oil or fat, to which, in said vessel or cooker, 331 gallons of 61% (by volume) alcohol are added. With continuous stirring, the mixture is heated to a temperature of about 40 0., whereupon 119 gallons of a caustic soda solution containing 4'76 pounds of sodium hydroxide are added to the oil and alcohol mixture. Stirring and heating of the mixture are continued, and the mixture is maintained at a temperature of about C. for about 30 minutes to insure complete saponification.

The mixture of soap solution is then cooled to a temperature of about 50 C. and diluted with 1042 gallons of 25% (by volume) alcohol. In the present specific example, atsuflicient vol-i ume of ethylene dichloride is added to the soap solution to raise the specific gravity of the mixture to 1.024 at a temperature of 72 F. A soap solution prepared as hereinabove outlined will absorb or hold in solution an amount of'ethylene dichloride equivalent to approximately 25% of its own volume. It will be understood, however, that a stronger soap solution would hold more ethylene dichloride and a weaker soap solution would hold less.

It is preferred to use as a specific gravity adjuster that amount of the material to be used as the extracting solvent which the soap solution will take up. In this connection it might be mentioned that the hotter the soap solution, the more solvent it will take up.

The adjustment of the specific gravity of the soap solution by the addition thereto of the extracting solvent, and particularly by the addition of the amount of the extracting solvent which the soap solution will take up, results in the elimination of disturbances during extraction, as hereinafter set forth, and insures a definite relation or equilibrium between the soap solution and the extracting solvent, thereby greatly facilitating the continuous, efiicient and complete extraction of the unsaponifiable fraction from the soap solution.

Continuing with the specific example of the invention and referring now particularly to the extraction of the unsaponifiable fraction from the soap solution, the accompanying drawing shows, more or less diagrammatically, a form of apparatus for carrying out such extraction-continuously and completely, in accordance with the invention.

The soap and ethylene dichloride mixture (or soap solution), made as above outlined, is transferred to a feed tank or reservoir A, from which, regulated by a valve 10, it flows down a conduit 12 and into the lower portion of a relatively long,-

upright extraction column 14.v From another feed tank or reservoir B the solvent (ethylene dichloride in the present example, specific grav-' ity 1.25) regulated by a valve 16, flows through a conduit 18 into the upper portion of the extraction column. By placing a quantity of Raschig rings 20 in the extraction column an intimate and thorough contact of the soap solution with the solvent is assured throughout the height of the column. .The Raschig rings act as deflecting baflies and prevent channellingof the two counter-currently flowing solutions owing to its higher specific gravity, the ethylene dichloride flows downwardly while the soap solution ascends. The eifect produced is that ofa continuing succession of intimate contacts and separations of the materials without the formation of an emulsion and without any other disturbance in the column. e

The ethylene dichloride, as it descends, extracts the unsaponifiable fraction from the soap solution and, with the extracted fraction, settles to the bottom of the column, from whichit continuously flows out through conduit 22, rising in the vertical portion of said conduit and entering the solvent extract container or reservoir C. The soap solution which has ascended to the top of the column is continuously withdrawn from the top"through'conduitflrtmmwhich it flows into the extracted soap cdmtainer or reservoir D.

It will be noted that the soap solution entering the column enters at the lower part thereof somewhat above the lowest part, and the solvent enters, the-,upper. portion of the extraction column somewhat below the-top thereof; whereas the solvent-extract is withdrawn from a point in the column lower than that at which the soap solution enters and the extracted soap leaves the upper portion of the extraction column at a point higher thanrthat at which the solvent enters the column.

In-starting operation, the extraction column is initially charged with a quantity of ethylene dichloride and the soap mixture is then introduced. When the soap solution withdrawn from the top of the column shows that the soap solution is free of the unsaponifiable fraction or vitamin potency, the process is then operated continuously. The test for presence of the unsaponifiable fraction in the soap solution withdrawn from the top of the column may be the colorimetric test with antimony chloride. If, asshown by this test, no vitamin A potency is present, it may be taken that there is likewise no ,1) potency present.

The extraction takes place effectively in all parts of the colunm. In the lower part of the column thedescending solvent solution has taken up a relatively large amount of the unsaponifiable fraction, but there comes in contact with fresh soap solution which, in the lower part of the column, contains the greatest amount of unsaponifiable matter to be extracted. The soap solution, as it ascends, contains less and less of the unsaponifiable fraction, but the less it contains, the less saturated is the solvent with which it comes-in contact. When the soap solution reaches the top of the colunm, it is free (of the order. of 99.9% free) of theunsaponiflable matter or vitamin potency.

The solvent extract, containing the extracted unsaponifiable fraction, may be concentrated (as by recovering the solvent in vacuo in a distilling apparatus) to 'any desired degree, and may be washed with water (or any salting-outagent, such as sodium chloride, sodium sulphate, calcium chloride, etc.) .to remove any soap that may be present in the solvent extract solution. Any remainingsolvent can be removed from the vitamin concentrate. by recovering the solvent L in a distilling'apparatus at a temperature below 60 C.

An important step in the process is theadjustment of the specific gravity of the soap solution by adding thereto an amount of the solvent to be used for extracting the unsaponifiable fraction. The more that is added: up to the limit of-the amount the soap solution will take up, the more 'eflicient the continuous process of extraction and the less the disturbance in the extraction column when "the soap solutionand solvent are brought "counter-currently into intimate contact. This adjustment, whencarried out to proper efficiency,' -results in a soapsolution from which the"'exti:acting solvent-'will'not solvents that can be used are sulphuric ether,

petroleum ether, carbon tetrachloride, orany other suitable immiscible solvent. Nor, is it necessary that the solvent solution have a specific gravity greater than the specific gravity of the soap solution, for the solvent solution may have a lower specific gravity, in which case it would enter the extraction column at the bottom, and the soap solution with a higher specific gravity would enter the extraction column at the top, as will be readily understood. Sulphuric ether, for example, has a lower specific gravity than the soap solution, whereas carbon tetrachloride has a higher specific gravity than the soap solution.

The adjustment of the specific gravity of the soap solution by the addition thereto of solvent for the unsaponifiable fraction not only insures adequate counter-current flow (scrubbing effect) in the extraction column, but, which is most important, prevents disturbances therein leading to an absorbing, dissolving or emulsifying of the solvent by the soap solution during operation of the continuous extraction process, thereby insuring continuous complete removal of all the unsaponifiable matter held in suspension in the soap solution.

-What is claimed is:

'1. In the preparation of a. vitamin concentrate from vitamin-containing material, the steps which comprise preparing from said material a soap solution, adding thereto a solvent iorthe unsaponifiable fraction in an amount within the limit of the quantity of said solvent the soap solution will take up, then extracting the unsaponifiable fraction from the soap solution by flowing continuously and counter-currently, in intimate contact past each other, the soap solution in a liquid state and more of the samesolvent in a liquid state, and thereafter concentrating the extracted unsaponifiable fraction.

2. In the preparation of a vitamin concentrate from vitamin-containing material, the steps which comprise preparing from said material a soap solution, adding thereto a suitable liquid in which the soap is soluble in an amount at least sufflcient to assure the soaps remaining homogeneously in solution at ordinary temperatures, then adding to said solution substantially the amount of a solvent for the unsaponiiiable frac-' tion that the soap solution will take up, then extracting the unsaponifiable fraction from the soap solution by flowing in intimate contact past each other, the soap solution in a liquid state and more of the same solvent in a liquid state, and thereafter concentrating the extracted unsaponifiable fraction.

3. In the preparation of a vitamin concentrate from vitamin-containing material, the steps which comprise adding alcohol to said material, preparing therefrom a soap solution, adding alcohol and water to said soap solution, then adding to said soap solution substantially that amount of ethylene dichloride which the soap solution will take up, thereafter flowing in intimate contact counter-currently past each other, said soap solution in a liquid state and ethylene dichloride in a liquid state to extract the unsaponifiable fraction, and concentrating the extracted -unsaponiflable fraction.

4.- In the preparation of a vitamin concentrate from cod liver oil, the steps which comprise heating and stirring 400 gallons of cod liver oil with 331 gallons of 61% (by volume) alcohol, forming a soap solution by adding, while heating and stirring, 119 gallons of caustic soda solution containing 4'76 pounds of sodium hydroxide, continuing the heating and stirring until saponification is complete, lowering the temperature of the soap solution, adding 1042 gallons of 25% (by volume) alcohol, then adding an amount of ethylene dichloride substantially equal to one-fourth the volume of the soap solution, thereafter flowing in intimate contact counter-currently past each other ethylene dichloride and said soap solution to extract the unsaponifiable fraction, and concentrating the unsaponiflable fraction.

CHARLES L. BARTHEN. 

